Systems and methods for providing electromagnetic interference shielding for integrated circuit modules

ABSTRACT

An automated system for maintaining paint thickness uniformity over the surface of a cap encapsulating at least one integrated circuit (IC) module on a panel of IC modules is provided. The system can be computer implemented and applies a layer of conductive paint that electrically couples with wirebonds on the panel to form at least part of an electromagnetic interference (EMI) or radio frequency interference (RFI) shield that attenuates EMI or RFI during operation of the IC module. The system optimizes the spray nozzle diameter, fluid pressure, coaxial air pressure, spray heights, speeds, and spray pattern achieves paint thickness control. A uniform coating of conductive paint provides a more effective EMI or RFI shield during the operation of the IC modules.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND

Conductive paint is widely used in the electronics industry forElectromagnetic Interference (EMI) shielding, Radio FrequencyInterference (RFI) shielding, and electrostatic discharge (ESD) control.For conductivity, the paint contains metal particles or flakes, and forhigh conductivity, the metal particles can be copper, nickel, silvercovered copper, silver or other expensive conductive materials. It isoften sprayed, brushed, or rolled onto plastic parts which are thenassembled into EMI or RFI shielded housings for sensitive electroniccircuits or devices.

SUMMARY

Conductive paint sprayed onto the surface of integrated circuit (IC)modules during the manufacturing process can provide at least part of ametal shield which reduces, attenuates or lessens EMI or RFI during theoperation of the integrated circuits.

To provide uniform coverage, conventional spray methods increase thedistance between the paint applicator and the surface to be painted.This greatly increases the overspray, consuming almost twice the volumeof paint that is actually required to cover a panel of IC modules, whichgreatly increases the price per unit for paint costs. To reduceoverspray, conventional methods decrease the distance between the paintapplicator and the surface to be painted. When this is done, track linesappear indicating there are hills and valleys in the paint surface. Theoverall paint thickness is not uniform, which does not provide a uniformEMI/RFI shield.

Certain embodiments relate to a method of spraying a surface withconductive paint. The method comprises spraying N axially elongate firstbands of conductive paint along a longitudinal axis of a surface andadvancing along a vertical axis of the surface a first distance afterspraying each first band of conductive paint. The method furthercomprises spraying N+1 axially elongate second bands of conductive paintalong the longitudinal axis of the surface and advancing along thevertical axis of the surface a second distance after each second band ofconductive paint. The second bands of conductive paint are interspersedbetween the first bands of conductive paint to provide an approximatelyuniform thickness of conductive paint on the surface. The method furthercomprises spraying the perimeter of the surface with third bands ofconductive paint. The steps of spraying the N first bands of conductivepaint, spraying the N+1 second bands of conductive paint, and sprayingthe perimeter with the third bands of conductive paint repeat until thedesired paint thickness is reached.

According to a number of embodiments, the disclosure relates to a methodof spraying a surface of a panel of integrated circuit (IC) modules withconductive paint to provide at least part of an electromagneticinterference (EMI) or radio frequency interference (RFI) shield thatattenuates EMI or RFI during operation of the IC module. The methodcomprises spraying N axially elongate first bands of conductive paintincluding metal particles along a longitudinal axis of a panel includingintegrated circuit (IC) modules and advancing along a vertical axis ofthe panel a first distance after spraying each first band of theconductive paint, and spraying N+1 axially elongate second bands of theconductive paint along the longitudinal axis of the panel and advancingalong the vertical axis of the panel a second distance after each secondband of the conductive paint. The second bands of the conductive paintare interspersed between the first bands of the conductive paint toprovide an approximately uniform layer of the conductive paint on anupper surface of the panel. The layer of conductive paint electricallycouples with wirebonds on the panel to form at least part of anelectromagnetic interference (EMI) or radio frequency interference (RFI)shield that attenuates EMI or RFI during operation of the IC module.

In accordance with various embodiments, a system for spraying a surfaceof a panel of integrated circuit (IC) modules with conductive paint toprovide at least part of an electromagnetic interference (EMI) or radiofrequency interference (RFI) shield that attenuates EMI or RFI duringoperation of the IC module is disclosed. The system comprises computerhardware including at least one computer processor, andcomputer-readable storage having computer-readable instructions that,when executed by the computer processor, cause the computer hardware toperform operations defined by the computer-executable instructions. Thecomputer-readable instructions include spraying N axially elongate firstbands of conductive paint including metal particles along a longitudinalaxis of a panel including integrated circuit (IC) modules and advancingalong a vertical axis of the panel a first distance after spraying eachfirst band of the conductive paint, and spraying N+1 axially elongatesecond bands of the conductive paint along the longitudinal axis of thepanel and advancing along the vertical axis of the panel a seconddistance after each second band of the conductive paint. The secondbands of the conductive paint are interspersed between the first bandsof the conductive paint to provide an approximately uniform layer of theconductive paint on an upper surface of the panel. The layer ofconductive paint electrically couples with wirebonds on the panel toform at least part of an electromagnetic interference (EMI) or radiofrequency interference (RFI) shield that attenuates EMI or RFI duringoperation of the IC module.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of a conductive layer formed over the overmoldsuch that the conductive layer is in electrical contact with the exposedupper portions of the EM isolation wirebonds.

FIG. 2 shows a process that can be implemented to fabricate a packagedmodule that includes an interconnected RF-shielding structure and/orshielded volume.

FIG. 3 a show front side of an example laminate panel configured toreceive a plurality of dies for formation of packaged modules.

FIGS. 4 and 5 show various views of the die electrically connected tothe laminate substrate by example wirebonds.

FIGS. 6 and 7 show various views of wirebonds formed on the laminatesubstrate and configured to facilitate electromagnetic (EM) isolationbetween an area defined by the wirebonds and areas outside of thewirebonds.

FIG. 8 shows a side view of molding configuration for introducingmolding compound to a region above the laminate substrate.

FIG. 9 shows a side view of an overmold formed via the moldingconfiguration of FIG. 8.

FIG. 10 shows the front side of a panel with the overmold.

FIG. 11 shows a detail of a side view of how an upper portion of theovermold can be removed to expose upper portions of the EM isolationwirebonds.

FIG. 12 shows a side view of how an upper portion of the overmold can beremoved to expose upper portions of the EM isolation wirebonds.

FIG. 13 shows a photograph of a portion of a panel where a portion ofthe overmold has its upper portion removed to better expose the upperportions of the EM isolation wirebonds.

FIG. 14 illustrates a schematic block diagram of a four section panelwith an upper portion of the overmold removed to better expose the upperportions of the EM isolation wirebonds.

FIG. 15 is a flow chart illustrating a process for forming a conductivelayer on a panel of IC modules, according to an embodiment.

FIG. 16A is a schematic diagram illustrating a first perimeter spraypattern for the process of FIG. 14, according to an embodiment.

FIG. 16B is a schematic diagram illustrating a staggered flood spraypattern for the process of FIG. 14, according to an embodiment.

FIG. 16C illustrates is a schematic diagram illustrating a secondperimeter spray pattern for the process of FIG. 14, according to anembodiment.

FIG. 16D is a schematic diagram illustrating a flood spray pattern forthe process of FIG. 4, according to an embodiment.

FIG. 17 is a partial cross-sectional view of a panel with modules afterthe process of FIG. 14, according to certain embodiments.

FIG. 18 shows a photograph of a panel where the conductive layer can bea spray-on metallic paint.

FIG. 19 is an exemplary table showing spray parameters, line parameters,and spray pattern parameters, according to an embodiment.

FIG. 20 is an exemplary table showing spray parameters, line parameters,and spray pattern parameters, according to another embodiment.

FIG. 21 shows individual packaged modules being cut from the panel.

FIG. 22 shows that one or more of modules that are mounted on a wirelessphone board can include one or more features as described herein.

FIG. 23 shows a process that can be implemented to install a packagedmodule having one or more features as described herein on a circuitboard such as the phone board of FIG. 22.

FIG. 24 schematically depicts the circuit board with the packaged moduleinstalled thereon.

FIG. 25 schematically depicts a wireless device having the circuit boardwith the packaged module installed thereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The features of the systems and methods will now be described withreference to the drawings summarized above. Throughout the drawings,reference numbers are re-used to indicate correspondence betweenreferenced elements. The drawings, associated descriptions, and specificimplementation are provided to illustrate embodiments of the inventionsand not to limit the scope of the disclosure.

Overview

FIG. 2 shows a process 10 that can be implemented to fabricate apackaged module having an interconnected RF-shielding structure and/orshielded volume that attenuates EMI or RFI during operation of the ICmodule as described herein. FIGS. 1 and 3-21 show various parts and/orstages of various steps associated with the process 10 of FIG. 2.

In block 12 h of FIG. 2, an electrically conductive layer can be formedon the new exposed upper surface of an overmold structure on a panel ofIC modules, so that the conductive layer is in electrical contact withthe upper portions of RF-shielding wirebonds adjacent to the IC module.Such a conductive layer can be formed by a number of differenttechniques, including methods such as spraying or printing. Sprayingconductive paint to form the conductive layer is described below.

FIG. 1 shows an example configuration 70 where an electricallyconductive layer 71 has been formed over an upper surface 65 of anovermold structure 59 encapsulating components of IC modules on asubstrate 20 having a ground plane 30. As described herein, the uppersurface 65 better exposes upper portions 66 of RF-shielding wirebonds51. Accordingly, the formed conductive layer 71 forms improved contactswith the upper portions 66 of the RF-shielding wirebonds 51.

The RF-shielding wirebonds 51 and the ground plane 30 can yield aninterconnected RF-shielding structure at sides and underside of the areadefined by the RF-shielding wirebonds 51. Connections between thecomponents and the ground plane 30 are depicted as dotted lines 31. Withthe upper conductive layer 71 in electrical contact with theRF-shielding wirebonds 51, the upper side above the area is now shieldedas well, thereby yielding a shielded volume.

In block 12 a of FIG. 2, a packaging substrate and parts to be mountedon the packaging substrate can be provided. Such parts can include, forexample, one or more surface-mount technology (SMT) components and oneor more singulated dies having integrated circuits (ICs). FIG. 3 showsthat in some embodiments, the packaging substrate can include a laminatepanel 16. FIG. 3 shows the example panel's front side. The panel 16 caninclude a plurality of individual module substrates 20 arranged ingroups that are sometimes referred to as cookies 18.

In block 12 b of FIG. 2, various steps can be performed to allowmounting of one or more SMT devices and one or more dies. The varioussteps can include but are not limited to applying solder paste on themodule substrate to allow mounting of one or more SMT devices,positioning one or more SMT devices on the solder contacts having solderpaste, performing a reflow operation to melt the solder paste to solderthe one or more SMT devices on their respective contact pads, removingsolder residue from the reflow operation, applying adhesive on one ormore selected areas on the module substrate 20 to allow mounting of oneor more dies, positioning one or more dies on the selected areas withadhesive applied thereon, curing the adhesive between the die and thedie-mounting area, removing adhesive residue from the mountingoperation, and the like.

In block 12 c of FIG. 2, electrical connections such as wirebonds can beformed between the mounted die(s) and corresponding contact pads on themodule substrate 20. FIGS. 4 and 5 show an example configuration 48where a number of wirebonds 49 are formed between the contact pads 37 ofthe die 36 and the contact pads 24 of the module substrate 20. Suchwirebonds can provide electrical connections for signals and/or power toand from one or more circuits of the die 36. In some implementations,the formation of the foregoing wirebonds can be achieved by an automatedwirebonding machine.

In block 12 d of FIG. 2, a plurality of RF-shielding wirebonds can beformed about a selected area on the module substrate 20. FIGS. 6 and 7show an example configuration 50 where a plurality of RF-shieldingwirebonds 51 is formed on wirebond pads 26. The wirebond pads 26 areschematically depicted as being electrically connected (dotted lines 31)with one or more reference planes such as a ground plane 30. In someembodiments, such a ground plane can be disposed within the modulesubstrate 20. The foregoing electrical connections between theRF-shielding wirebonds 51 and the ground plane 30 can yield aninterconnected RF-shielding structure at sides and underside of the areadefined by the RF-shielding wirebonds 51. As described herein, aconductive layer can be formed above such an area and connected to upperportions of the RF-shielding wirebonds 51 to thereby form an RF-shieldedvolume.

In the example configuration 50, the RF-shielding wirebonds 51 are shownto form a perimeter around the area where the die (36) and the SMTdevices (43) are located. Other perimeter configurations are alsopossible. For example, a perimeter can be formed with RF-wirebondsaround the die, around one or more of the SMT devices, or anycombination thereof. In some implementations, an RF-wirebond-basedperimeter can be formed around any circuit, device, component or areawhere RF-isolation is desired. For the purpose of description, it willbe understood that RF-isolation can include keeping RF signals or noisefrom entering or leaving a given shielded area.

In the example configuration 50, the RF-shielding wirebonds 51 are shownto have an asymmetrical side profile configured to facilitate controlleddeformation during a molding process as described herein. Additionaldetails concerning such wirebonds can be found in, for example, PCTPublication No. WO 2010/014103 titled “SEMICONDUCTOR PACKAGE WITHINTEGRATED INTERFERENCE SHIELDING AND METHOD OF MANUFACTURE THEREOF.” Insome embodiments, other shaped RF-shielding wirebonds can also beutilized. For example, generally symmetric arch-shaped wirebonds asdescribed in U.S. Pat. No. 8,071,431, titled “OVERMOLDED SEMICONDUCTORPACKAGE WITH A WIREBOND CAGE FOR EMI SHIELDING,” can be used asRF-shielding wirebonds in place of or in combination with the shownasymmetric wirebonds. In some embodiments, RF-shielding wirebonds do notnecessarily need to form a loop shape and have both ends on the surfaceof the module substrate. For example, wire extensions with one end onthe surface of the module substrate and the other end positioned abovethe surface (for connecting to an upper conductive layer) can also beutilized.

In the example configuration 50 of FIGS. 6 and 7, the RF-shieldingwirebonds 51 are shown to have similar heights that are generally higherthan heights of the die-connecting wirebonds (49). Such a configurationallows the die-connecting wirebonds (49) to be encapsulated by moldingcompound as described herein, and be isolated from an upper conductivelayer to be formed after the molding process.

In block 12 e of FIG. 2, an overmold can be formed over the SMTcomponent(s), die(s), and RF-shielding wirebonds. FIG. 8 shows anexample configuration 52 that can facilitate formation of such anovermold. A mold cap 53 is shown to be positioned above the modulesubstrate 20 so that the lower surface 54 of the mold cap 53 and theupper surface 21 of the module substrate 20 define a volume 55 wheremolding compound can be introduced.

In some implementations, the mold cap 53 can be positioned so that itslower surface 54 engages and pushes down on the upper portions of theRF-shielding wirebonds 51. Such a configuration allows whatever heightvariations in the RF-shielding wirebonds 51 to be removed so that theupper portions touching the lower surface 54 of the mold cap 53 are atsubstantially the same height. When the mold compound is introduced andan overmold structure is formed, the foregoing technique maintains theupper portions of the encapsulated RF-shielding wirebonds 51 at or closeto the resulting upper surface of the overmold structure.

In the example molding configuration 52 of FIG. 8, molding compound canbe introduced from one or more sides of the molding volume 55 asindicated by arrows 56. In some implementations, such an introduction ofmolding compound can be performed under heated and vacuum condition tofacilitate easier flow of the heated molding compound into the volume55.

FIG. 9 shows an example configuration 58 where molding compound has beenintroduced into the volume 55 as described in reference to FIG. 8 andthe molding cap removed to yield an overmold structure 59 thatencapsulates the various parts (e.g., die, die-connecting wirebonds, andSMT devices). The RF-shielding wirebonds are also shown to besubstantially encapsulated by the overmold structure 59. The upperportions of the RF-shielding wirebonds are shown to be at or close tothe upper surface 60 of the overmold structure 59.

FIG. 10 shows an example panel 62 that has overmold structures 59 formedover the multiple cookie sections. Each cookie section's overmoldstructure can be formed as described herein in reference to FIGS. 8 and9. The resulting overmold structure 59 is shown to define a common uppersurface 60 that covers the multiple modules of a given cookie section.

The molding process described herein in reference to FIGS. 8-10 canyield a configuration where upper portions of the encapsulatedRF-shielding wirebonds are at or close to the upper surface of theovermold structure. Such a configuration may or may not result in theRF-shielding wirebonds forming a reliable electrical connection with anupper conductor layer to be formed thereon.

In block 12 f of FIG. 2, a top portion of the overmold structure can beremoved to better expose upper portions of the RF-shielding wirebonds.FIG. 12 shows an example configuration 64 where such a removal has beenperformed. FIG. 11 shows an enlarged detail of the example configuration64. In the example, the upper portion of the overmold structure 59 isshown to be removed to yield a new upper surface 65 that is lower thanthe original upper surface 60 (from the molding process). Such a removalof material is shown to better expose the upper portions 66 of theRF-shielding wirebonds 51.

The foregoing removal of material from the upper portion of the overmoldstructure 59 can be achieved in a number of ways. FIG. 13 shows anexample configuration 68 where such removal of material is achieved bysand-blasting. The example configuration 68 illustrates where materialhas been removed to yield the new upper surface 65 and to better exposeupper portions 66 of the RF-shielding wirebonds. The exampleconfiguration 68 also illustrates where material has not been removed,so that the original upper surface 60 still remains. The regionindicated as 69 is where the material-removal is being performed.

In the example shown in FIG. 13, a modular structure corresponding tothe underlying module substrate 20 (depicted with a dotted box 22) isreadily shown. Such modules will be separated after a conductive layeris formed over the newly formed upper surface 65.

In block 12 g of FIG. 2, the new exposed upper surface resulting fromthe removal of material can be cleaned to yield a cleaner surface tofacilitate improved adhesion of a conductive layer formed thereon.

In block 12 h of FIG. 2, an electrically conductive layer can be formedon the new exposed upper surface of the overmold structure, so that theconductive layer is in electrical contact with the upper portions of theRF-shielding wirebonds. Such a conductive layer can be formed by anumber of different techniques, including methods such as spraying orprinting.

Spraying conductive paint on the surface of an IC panel to form theconductive layer as at least part of an EMI/RF shield is described infurther detail below. Although certain embodiments are described hereinwith respect to the exemplary panel 1400 illustrated in FIG. 14, it isunderstood that in other embodiments, the panel of IC modules can havedifferent dimensions, a different number of cookies, and each cookie caninclude different quantities of IC modules than the illustrated panel1400.

FIG. 14 illustrates a schematic block diagram of an embodiment of a foursection panel 1400 formed after completion of block 12 f of FIG. 2. Inthe illustrated embodiment, panel 1400 comprises a module substrate 1402and four abraded encapsulated sections or cookies 1404. Each cookie 1404comprises at least one integrated circuit 1406 mounted to the substrate1402, a cap or overmold 1408, and at least one RF-shielding wirebond 51.

The panel 1400 has a cookie length, L, along the longitudinal axis ofthe substrate 1402 of approximately 7.10 inches and a cookie height, H,along the vertical axis of the substrate 1402 of approximately 2.05inches. In other embodiments, the panel dimensions can be other values.Typically, each cookie 1404 can comprise between approximately 4 andapproximately 300 integrated circuits. In another embodiments, the panel1400 can comprise less than or more than four cookies 1404. In furtherembodiments, each cookie 1404 can comprise less than 4 or more than 300IC modules 1406.

In an embodiment, forming the conductive layer comprises covering thesurface of the overmold 1408 with an approximately uniform or nearlyuniform layer of conductive paint using a spray process. In anembodiment, the conductive paint is sprayed onto the surfaces 1408 ofthe panel 1400 during module manufacturing as at least part of an RFI orEMI shield for the IC modules 1406. Unlike conventional spray paint, theconductive paint includes metal particles or flakes and can be much moreexpensive. A conductive paint can contain flakes with an average size ora range of sizes. Flake sizes can vary from less than approximately 1micron, approximately 1 micron to approximately 10 microns,approximately 10 microns to approximately 60 microns, and greater thanapproximately 60 microns. While in some embodiments, the flakes orparticles are uniform in shape, in other embodiments, the flakes orparticles are irregularly shaped. When the conductive paint is applied,a more efficient RFI or EMI shield is created for the IC modules 1406 ifthe flakes overlap to provide coverage of the surfaces 1408 without gapsor with small gaps between the flakes.

For example, a thin layer of corn flakes on a table surface where noneof the flakes overlap does not cover the table surface. There are manygaps between the flakes where the table shows. Whereas a layer of cornflakes with an approximately uniform thickness such that the flakesoverlap one another can provide total coverage, effective totalcoverage, or coverage that approximates total coverage of the tablesurface. While corn flakes are not conductive metal particles, thecoverage analogy is applicable to the conductive paint. A layer ofconductive paint including metal flakes where the conductive paint isapplied with an approximate uniform thickness such that the metal flakesoverlap one another can provide total coverage, effective totalcoverage, or coverage that approximates total coverage of the surface ofthe IC module 1406. This in turn provides a conductive surface inelectrical contact with the wirebonds 51 for each IC module 1406,forming at least part of an EMI/RFI shield structure or volume for eachIC module 1406.

Another quality of the conductive paint which affects the paint coverageis the paint viscosity. This may be an inherent quality of the paint ormay be user adjustable with the addition of a suitable paint thinner. Amore viscous paint will flow more slowly than a less viscous paint andmay increase manufacturing throughput time, which in turn increasesmanufacturing costs. The less viscous paint may flow more quickly thanthe more viscous paint, but may provide spotty paint and/or spottyconductive particle coverage, which may provide poor EMI or RFIshielding.

Due to the expense of the conductive paint, it is desirable to reducethe overspray. Overspray is the application of the conductive paint toany surface other than the surfaces 1408 on the panel 1400. Theconventional method of reducing the overspray is to apply the paintcloser to the surface to be painted such that the spread of the spray isreduced. This also creates a non-uniform surface with peaks and valleysin the applied paint.

Due to the use of the conductive paint as an EMI or RFI shield, it isdesirable to form a uniform or approximately uniform layer of conductivemetal particles over the IC modules 1406 with no or small gaps betweenthe metal particles as described above. The conventional method ofapplying a uniform layer of a sprayed material is to apply the paintfarther from the surface to be painted such that the spread of the sprayis increased. This also increases the overspray.

In one embodiment, a paint sprayer comprising a spray head and a paintdelivery system delivers the conductive paint to the IC panel 1400.Examples of paint sprayer spray heads are standard flux material sprayheads, automated spray booths, jetting systems, and the like. Examplesof paint delivery systems are an air atomization delivery system, anultrasonic atomization paint delivery system, a regular air spray paintdelivery system, automotive spray systems, and the like. In anembodiment, the paint sprayer is computer controlled and userprogrammable, where the user program is executed by the paint sprayercomputer. The spray head comprises a spray nozzle and the spray nozzleincludes a needle from which the paint enters the delivery system.Needles of various sizes can be used. The size of the needle depends atleast in part on the size of the conductive particles in the paintand/or at least in part on the viscosity of the paint. If the needle istoo small, the particles will clog the needle. The size of the needlealso depends in part on the desired rate at which the paint exits theneedle. A larger needle provides a greater rate of paint flow than asmaller needle. In one embodiment, needle sizes range from approximately14 gauge to approximately 32 gauge. In other embodiments, larger orsmaller needles can be used.

Paint sprayers include additional factors that may be an inherentquality of the type of paint sprayer, or may be user settable. Forexample, in a paint sprayer with an air atomizer paint delivery system,in addition to choosing the needle size, the user may vary factors, suchas, for example, the valve pressure, the air cap, the fluid pressure,the air assist pressure, and the like. The valve pressure controls therate in which the seat valve opens and closes to allow the paint to flowto the nozzle. The air cap is measured in degrees and varies the angleof the cavity used to atomize the paint. The fluid pressure is thepressure applied to the paint reservoir to control the rate theconductive paint is pushed through the nozzle when the seat valve isopened and the air assist pressure is the pressure applied to the aircap to atomize the paint to apply it to the IC panel 1400.

In addition, the user can adjust the speed at which the spray headtravels and the distance of the spray head above the surface to bepainted. As described above, when the spray head is too far above thesurface to be painted, the paint spreads and oversprays. When the sprayhead is too close to the surface to be painted, the spray is lessuniform. There are tradeoffs with the speed also. The faster the sprayhead travels, the throughput of modules during manufacturing increases,but a thinner paint line is laid down, creating non-uniform paint andconductive particle coverage.

Further factors include line parameters, such as a fluid on time, afluid off time, an air assist on time, and an air assist off time. Thefluid on time is the amount of time from the start of the spray headtravel and to the start of the spray. The fluid off time is the timefrom the stop of the spray to the stop of the spray head travel.Similarly, the air assist on time is the time from the start of thespray head travel to the start of the flow of the air providing theatomization, and the air assist off time is the time from the stop ofthe flow of air providing the atomization to the stop of the spray headtravel.

Once the above parameters are chosen for a desired paint line, takinginto account the line width, overspray width, thickness, and uniformityof coverage for the line, the process in FIG. 2 block 12 h can achieve atight spray pattern that minimizes overspray and maintains acceptablepaint thickness uniformity for the painted surfaces 1408. In anembodiment, the above parameters are chosen to optimize oversprayreduction and uniform paint coverage for a perimeter paint spray patternand surface area spray patterns, such as, a flood paint spray patternand a staggered flood paint spray pattern, respectively for the panel1400 of IC modules 1406.

FIG. 2 block 12 h illustrates forming a conductive layer on the exposedsurfaces 1408 of a panel 1400 of IC modules 1406 during the modulefabrication process. FIG. 15 is a flow chart illustrating an embodimentof FIG. 2 block 12 h in further detail. FIG. 15 illustrates the processused to spray conductive paint in spray patterns which form a uniform ornearly uniform or substantially uniform conductive layer having littleor no overspray.

FIGS. 16A-16D are schematic diagrams illustrating embodiments of thespray patterns for the panel 1400 of FIG. 14. FIG. 16A is a schematicdiagram illustrating an embodiment of a first perimeter spray 1600. FIG.16B is a schematic diagram illustrating an embodiment of a staggeredflood spray 1620. FIG. 16C illustrates is a schematic diagramillustrating an embodiment of a second perimeter spray 1640 and FIG. 16Dis a schematic diagram illustrating an embodiment of a flood spray 1660.

Referring to FIGS. 14, 15 and 16A, the process 12 h at block 1500 spraysconductive paint in a perimeter spray pattern 1600 over the surfaces1408 of the panel 1400. The spray paint apparatus sprays a firsthorizontal band of paint 1602 having a width W1 from approximately pointA (0, 0) to approximately point B (L, 0). The first horizontal band 1602is approximately parallel to the longitudinal or horizontal axis of thepanel 1400.

The beginning of the band 1602 is approximately at point A and the endof the band 1602 is approximately at point B because the actualbeginning and ending points of the band 1602 are adjusted upward alongthe vertical axis toward points D and C, respectively, at least aportion of the width W1. Further, the actual beginning point of the band1602 is adjusted outward along the longitudinal axis toward point B atleast a portion of the width W1 and the actual ending point of the band1602 is further adjusted inward along the longitudinal axis toward pointA at least a portion of the width W1.

The spray paint apparatus then sprays a first vertical band of paint1604 having about width W1 from approximately point B (L,0) toapproximately point C (L,H). The first vertical band 1604 isapproximately parallel to the vertical axis of the panel 1400 andapproximately perpendicular to the longitudinal or horizontal axis ofthe panel 1400.

The beginning of the band 1602 is approximately at point B and the endof the band 1602 is approximately at point C because the actualbeginning and ending points of the band 1602 are adjusted inward alongthe longitudinal axis toward points A and D, respectively, at least aportion of the width W1. Further, the actual beginning point of the band1604 is adjusted upward along the vertical axis toward point C at leasta portion of the width W1 and the actual ending point of the band 1604is further adjusted downward along the vertical axis toward point B atleast a portion of the width W1.

The spray paint apparatus then sprays a second horizontal band of paint1606 having about width W1 from approximately point C (L,H) toapproximately point D (0,H). The second horizontal band 1606 isapproximately parallel to the longitudinal or horizontal axis of thepanel 1400.

The beginning of the band 1606 is approximately at point C and the endof the band 1606 is approximately at point D because the actualbeginning and ending points of the band 1606 are adjusted downward alongthe vertical axis toward points B and A, respectively, at least aportion of the width W1. Further, the actual beginning point of the band1606 is adjusted inward along the longitudinal axis toward point D atleast a portion of the width W1 and the actual ending point of the band1606 is further adjusted inward along the longitudinal axis toward pointA at least a portion of the width W1.

The spray paint apparatus then sprays a second vertical band of paint1608 having about width W1 from approximately point D (0,H) toapproximately point A (0,0). The second vertical band 1608 isapproximately parallel to the vertical axis of the panel 1400 andapproximately perpendicular to the longitudinal or horizontal axis ofthe panel 1400.

The beginning of the band 1608 is approximately at point D and the endof the band 1608 is approximately at point A because the actualbeginning and ending points of the band 1608 are adjusted outward alongthe longitudinal axis toward points C and B at least a portion of thewidth W1. Further, the actual beginning point of the band 1608 isadjusted downward along the vertical axis toward point A at least aportion of the width W1 and the actual ending point of the band 608 isfurther adjusted upward along the vertical axis toward point D at leasta portion of the width W1.

The adjustments of the beginning and ending locations of the bands 1602,1604, 1606, 1608 reduce or in some embodiments eliminate overspray alongthe perimeter of the group of cookies 1404. In addition, theseadjustments prevent the perimeter bands of paint 1602, 1604, 1606, 1608from overlapping, which would cause an additional layer of paint to beapplied at the corners A, B, C, D of the group of cookies 1404.

In the described embodiment, the width W1 of the bands 1602, 1604, 1606,1608 is approximately the same. In other embodiments, each band 1602,1604, 1606, 1608 can have a differing width. In some embodiments, thewidth W1 is based at least in part on the height Z of the spray headabove IC panel 1400. Although the order of spraying of the perimeterbands in the described embodiment occurs with band 1602 being sprayedfirst, followed by band 1604, which is then followed by band 1606 andending with band 1608, the order of the spraying of the bands 1602,1604, 1606, 1608 can be different in other embodiments.

Referring again to FIGS. 14, 15 and 16B, the process 12 h at block 1502performs a staggered flood spray pattern 1620. The staggered flood spraypattern 1620 comprises n lines of paint which are sprayed in alternatingleft to right and right to left bands which are approximately parallelto each other and the longitudinal axis of the panel 1400. In anembodiment, the spray head sprays the first band of the staggered floodspray pattern 1620 near the lower edge of the panel 1400 and subsequentbands advance upward over the surface of the panel 1400. In otherembodiments, the spray begins near the top, the middle, or any otherpoint of the panel 1400 and travels so as to cover the surfaces 1408 ofthe panel 1400.

In the embodiment illustrated in FIG. 16B, n=9, or in other words, thestaggered flood spray pattern 1620 comprises 9 paint bands. In otherembodiments, n can be more or less than 9. The number of bands, n, ofthe staggered flood spray pattern 1620 depends at least in part on theheight, H, of the panel 1400 and/or on the width of the spray line.

Referring to FIG. 16B, the spray paint apparatus sprays a firsthorizontal band of paint 1622 having a width W2 from approximately pointB (L,0) to approximately point A (0,0). The first horizontal band 1622is approximately parallel to the longitudinal or horizontal axis of thepanel 1400.

The beginning of the band 1622 is approximately at point B and the endof the band 1622 is approximately at point A because the actualbeginning and ending points of the band 1622 are adjusted upward alongthe vertical axis toward points D and C, respectively, to take intoaccount the width W1 of the perimeter spray, the width W2 of thestaggered flood spray bands, and line spacing LS1 of the staggered spraypattern 1620. Further, the actual beginning point of the band 1622 isadjusted inward along the longitudinal axis toward point A and theactual ending point of the band 1622 is adjusted outward along thelongitudinal axis toward point B to take into account the width W1 ofthe perimeter spray.

In the illustrated embodiment, the first band 1622 begins atapproximately (L−W1, 0.08+W1+½ LS1), where L is the length of the panel,W1 is the width of the perimeter spray band of paint, and LS1 is theline spacing of the staggered flood spray pattern 1620. The startingpoint coordinates may vary depending on the (0, 0) coordinates of thespray paint apparatus and the IC panel 1400 being painted. The firstband 1622 ends at approximately (W1, 0.08+W1+½ LS1). The spray headadvances upward along the vertical axis of the panel 1400 to spray thenext band in the staggered flood spray pattern 1620. The spray headmoves upward a distance approximately equal to the line spacing, LS1,and sprays a band of paint approximately parallel to the longitudinalaxis of the panel 1400 ending at the beginning of the previous band butoffset by the line spacing, LS1, above the previous line 1622.

This process repeats until the spray head applies n bands of paint tothe surface of the panel 1400, where each band of paint in the staggeredflood spray pattern 1620 is offset from the previous band of paint bythe line spacing, LS1.

In the illustrated embodiment, the bands of paint in the staggered floodspray pattern 1640 are sprayed in an alternating left to right and rightto left pattern. In another embodiment, the bands can be sprayed in analternating right to left and left to right pattern. In yet otherembodiments, each band can be sprayed from left to right, from right toleft, or in any combination of left to right or right to left spraypatterns.

Referring again to FIGS. 14, 15 and 16C, the process 12 h at block 1504performs a second perimeter spray pattern 1640. In an embodiment, thesecond perimeter spray pattern 1640 is the same as the first perimeterspray pattern 1600 described above. In other embodiments, the secondperimeter spray pattern 1640 can have different beginning and endingpoints, a different order of application, wider or narrower band widths,or the like, than the first perimeter spray pattern 1600.

In the embodiment illustrated in FIG. 16C, the second perimeter spraypattern 640 comprises four perimeter bands of paint, 1642, 1644,1646,1648. The second perimeter bands 1642, 1644, 1646, 1648 correspondto the bands 1602, 1604, 1606, 1608 of the first perimeter spray pattern1600, respectively, and are applied as described above with respect tothe first perimeter spray pattern 1600. The processes of spraying thefirst and second perimeter spray patterns 1600, 1640 provide spray edgecontrol that facilitates high volume manufacturing and reduces paintoverspray. The reduction in paint overspray reduces paint waste, whichprovides cost savings.

Referring again to FIGS. 14, 15 and 16D, the process 12 h at block 1506performs a flood spray pattern 1660. The flood spray pattern 1640comprises n+1 lines of paint which are sprayed in alternating left toright and right to left which are approximately parallel to each otherand the longitudinal axis of the panel 1400 and have a width W3. The n+1bands of the flood spray pattern 1660 interleave before, after, andbetween the n bands of the staggered flood spray pattern 620 to providenear uniform coverage of the panel 1400.

In the embodiment illustrated in FIG. 6D, n=9, or in other words, theflood spray pattern 1660 comprises n+1=10 paint bands. While in otherembodiments, n can be greater or less than 9, the relationship betweenthe number of bands in the staggered flood spray pattern 1620 and thenumber in bands in the flood spray pattern 1660 is n:n+1. The number ofbands, n+1, of the flood spray pattern 1660 depends at least in part onthe height H of the panel 1400 and/or on the width of the spray line W3.

The number of bands or paint lines, n+1, in the flood spray pattern isdetermined by rounding up to the next integer value the result of[H−2W1]/W3 where H is the height of the panel 400, W1 is the width ofthe perimeter spray bands 1602, 1604, 1606, 1608, 1642, 1644, 1646,1648, and W3 is the width of bands in the flood spray pattern 1660. Theline spacing, LS2, between the bands of the flood spray pattern 1660 is[H−2W1]/[n+1].

In an embodiment, the spray head sprays the first band of the staggeredflood spray pattern 1660 near the lower edge of the panel 1400 andsubsequent bands advance upward over the surface of the panel 1400. Inother embodiments, the spray begins near the top, the middle, or anyother point of the panel 1400 and travels so as to cover the surface ofthe panel 1400. In an embodiment, the bands of paint in the flood spraypattern 1660 are sprayed in an alternating left to right and right toleft pattern. In another embodiment, the bands can be sprayed in analternating right to left and left to right pattern. In yet otherembodiments, each band can be sprayed from left to right, from right toleft, or in any combination of left to right or right to left spraypatterns.

In the embodiment illustrated in FIG. 16D, the spray head beginstraveling left to right. A first band 1662 begins at approximately (0,0.08+W1+½ LS2) and ends at approximately (L−W1, 0.08+W1+½ LS2) where W1is the width of bands in the perimeter spray 1600, 1620, LS2 is the linespacing of the flood spray pattern 1660, and L is the length of thepanel 1400. The spray head advances upward along the vertical axis ofthe panel 1400 to spray the next band in the flood spray pattern 1660.The spray head moves upward a distance approximately equal to the linespacing, LS2, and sprays a band of paint approximately parallel to thelongitudinal axis of the panel 1400 ending at the beginning of theprevious band but offset by the line spacing, LS2, above the previousline 1662.

This process repeats until the spray head applies n+1 bands of paint tothe surface of the panel 1400, where each band of paint in the floodspray pattern 660 is offset from the previous band of paint by the linespacing, LS2.

In the illustrated embodiment, the width W2 of the paint band in thestaggered flood spray 1640 is approximately the same as the width W3 ofthe paint bands in the flood spray 1660. In other embodiments, thewidths W2, W3 are not the same. In some embodiments, the widths W2, W3are based at least in part on the height Z of the spray head above ICpanel 1400. In a preferred embodiment, the staggered flood spray 1640precedes the flood spray 1660. In other embodiments, the order of theperimeter sprays 1600, 1640, the staggered flood spray 1620, and theflood spray 1660 can vary.

Referring to FIG. 5, in block 1508 the process 12 h determines whetherthe desired paint thickness has been reached. If the desired paintthickness has not been reached, the process returns to block 1500, whereblocks 1502-1506 are repeated until the desired paint thickness has beenreached. If the desired paint thickness has been reached, the process 12h ends at block 1510.

FIG. 17 is an exemplary cross-sectional view of the panel 1400 after theprocess of FIG. 15. The panel 1400 comprises the mold cap 1408 encasingthe IC modules 1406 and the wirebonds 51 on the substrate 1402. Thepanel 1400 further comprises the bands of paint from the first perimeterspray 1600, the staggered flood spray 1620, the second perimeter spray1640, and the flood spray 1660. The bands of perimeter spray pattern1640 are over the bands of perimeter spray pattern 1600. The perimetersprays 1600, 1640 provide little or no overspray.

In the embodiment illustrated in FIG. 17, n=9. The 9 bands of thestaggered flood spray pattern 1620 are next to the overmold 1408, whilethe 10 bands of the flood spray pattern 1660 are above the staggeredflood spray bands and cover any gaps in created by the irregular metalparticles or flakes in the conductive paint. The 9 bands of conductivepaint in the staggered flood spray pattern 1620 and the 10 bands ofconductive paint in the flood spray pattern 1660 interleave to provide anearly or approximately or substantially uniform paint thickness overthe surface of the caps 1408. The nearly or approximately orsubstantially uniform paint thickness provides a nearly or approximatelyuniform conductive layer 71 over the panel 1400.

As illustrated if FIG. 17, the thickness of each of the bands 1600,1620, 1640, 1660 of conductive paint is greater toward the middle of theband and tapers off toward the sides of the band. As a result, theconductive paint forms a layer on the surfaces 1408 of the panel 1400that is approximately uniform or approximately flat within a tolerancethat accounts for the variations in the thickness of the band of paint.The flatness tolerance is the distance between two parallel planeswithin which the surface of the layer of conductive paint lies. In anembodiment, the conductive layer 71 has a thickness of approximately 30microns±15 microns. In another embodiment, the conductive layer 71 has athickness of approximately 5 microns to approximately 50 microns and aflatness of approximately 5 microns. In other words, the conductivepaint layer 71 is between approximately 5 microns and 50 microns thickand the surface of the layer of paint lies within two parallel planesspaced approximately 5 microns apart. More preferably the thickness ofthe conductive layer 71 is approximately 20 microns to approximately 30microns with a flatness of approximately 1 micron, and most preferably,the thickness of the conductive layer 71 is approximately 25 micronswith a flatness of approximately 0.25 micron. In an embodiment, theflatness of the conductive layer ranges between approximately 0.25micron and approximately 5 microns. In another embodiment, the flatnessis approximately 1% of the thickness of the conductive paint layer 71.

FIG. 18 is an exemplary table showing spray parameters, line parameters,and spray pattern parameters, according to one embodiment. The paintsprayer has a valve pressure of approximately 75 psi, a 21 gauge needle,and an air gap of approximately 22.5°. The paint reservoir ispressurized to approximately 2.5 psi and the air assist is pressurizedto approximately 4 psi. In this embodiment, n=9, such that the staggeredflood spray pattern 1640 comprises 9 bands of paint and the flood spraypattern comprises 10 bands of paint.

The spray parameters and the line parameters are set for each spraypattern, 1600, 1620, 1640, 1660. Here, the first and the secondperimeter spray patterns 1600, 1640 are the same. For each perimeterspray pattern 1600, 1640, the spray speed is approximately 30 inches persecond and the spray head is approximately 0.25 inches above the panel1400. For each perimeter spray pattern 1600, 1640, the paint spray isenabled 10 msec after the spray head begins to travel and is disabledapproximately 7.5 msec before the end of the spray head travel. The airassist is enabled 10 msec after the spray head begins to travel anddisabled 7.5 msec before the end of the spray head travel. The tablefurther lists the coordinates of the beginning and ending points for theperimeter bands, 1602, 1604, 1606, 1608, 1642, 1644, 1646, 1648. Forexample, the first perimeter band 602 begins at approximately (0.09,0.18) and ends at approximately (7.15, 0.18).

For the staggered flood spray pattern 1620, the spray speed isapproximately 30 inches per second and the spray head is approximately0.4 inches above the panel 1400. The paint spray is enabled 5 msec afterthe spray head begins to travel and is disabled approximately 8 msecbefore the end of the spray head travel. The air assist is enabled 5msec after the spray head begins to travel and disabled 8 msec beforethe end of the spray head travel. The table further lists thecoordinates of the beginning and ending points for the 9 staggered floodspray pattern bands. For example, the first staggered flood spray band1622 begins at approximately (7.1, 0.37) and ends at approximately (0.1,0.37).

For the flood spray pattern 1660, the spray speed is approximately 30inches per second and the spray head is approximately 0.4 inches abovethe panel 1400. The paint spray is enabled 5 msec after the spray headbegins to travel and is disabled approximately 8 msec before the end ofthe spray head travel. The air assist is enabled 5 msec after the sprayhead begins to travel and disabled 8 msec before the end of the sprayhead travel. The table further lists the coordinates of the beginningand ending points for the 10 flood spray pattern bands. For example, thefirst flood spray band 1662 begins at approximately (0.1. 0.275) andends at approximately (7.1, 0.275).

FIG. 19 is another exemplary table showing spray parameters, lineparameters, and spray pattern parameters, according to anotherembodiment. The paint sprayer has a valve pressure of approximately 75psi, a 21 gauge needle, and an air gap of approximately 22.5°. The paintreservoir is pressurized to approximately 2 psi and the air assist ispressurized to approximately 3 psi. In this embodiment, n=9, such thatthe staggered flood spray pattern 640 comprises 9 bands of paint and theflood spray pattern comprises 10 bands of paint.

The spray parameters and the line parameters are set for each spraypattern, 1600, 1620, 1640, 1660. Here, the first and the secondperimeter spray patterns 1600, 1640 are the same. For each perimeterspray pattern 1600, 1640, the spray speed is approximately 30 inches persecond and the spray head is approximately 0.25 inches above the panel1400. For each perimeter spray pattern 1600, 1640, the paint spray isenabled approximately 6.37 msec after the spray head begins to traveland is disabled approximately 8.25 msec before the end of the spray headtravel. The air assist is enabled approximately 6.37 msec after thespray head begins to travel and disabled approximately 6.25 msec beforethe end of the spray head travel. The table further lists thecoordinates of the beginning and ending points for the perimeter bands,1602, 1604, 1606, 1608, 1642, 1644, 1646, 1648. For example, the firstperimeter band 1602 begins at approximately (0.080, 0.200) and ends atapproximately (7.160, 0.200).

For the staggered flood spray pattern 1620, the spray speed isapproximately 30 inches per second and the spray head is approximately0.4 inches above the panel 1400. The paint spray is enabled 5.26 msecafter the spray head begins to travel and is disabled approximately 10.0msec before the end of the spray head travel. The air assist is enabled5.26 msec after the spray head begins to travel and disabled 7 msecbefore the end of the spray head travel. The table further lists thecoordinates of the beginning and ending points for the 9 staggered floodspray pattern bands. For example, the first staggered flood spray band1622 begins at approximately (7.055, 0.370) and ends at approximately(0.170, 0.370).

For the flood spray pattern 1660, the spray speed is approximately 30inches per second and the spray head is approximately 0.4 inches abovethe panel 1400. The paint spray is enabled approximately 5.26 msec afterthe spray head begins to travel and is disabled approximately 10.0 msecbefore the end of the spray head travel. The air assist is enabledapproximately 5.26 msec after the spray head begins to travel anddisabled approximately 7 msec before the end of the spray head travel.The table further lists the coordinates of the beginning and endingpoints for the 10 flood spray pattern bands. For example, the firstflood spray band 1662 begins at approximately (0.170, 0.275) and ends atapproximately (7.055, 0.275).

FIG. 20 shows an example panel 72 that has been sprayed with conductivepaint to yield the electrically conductive layer 71 that covers multiplecookie sections. As described in reference to FIG. 14, each cookiesection 1404 includes multiple IC modules 1406 that will be separated.

In block 12 i of FIG. 2, the modules in a cookie section having a commonconductive layer (e.g., a conductive paint layer) can be singulated intoindividual packaged modules. Such singulation of modules can be achievedin a number of ways, including a sawing technique.

FIG. 21 shows an example configuration 74 where the modular section 20described herein has been singulated into a separated module 75. Theovermold portion 59 is shown to include a side wall 77; and the modulesubstrate portion 20 is shown to include a side wall 76. Collectively,the side walls 77 and 76 are shown to define a side wall 78 of theseparated module 75. The upper portion of the separated module 75remains covered by the conductive layer 71. The lower surface 27 of theseparated module 75 includes contact pads 28, 29 to facilitateelectrical connections between the module 75 and a circuit board such asa phone board.

As described herein, such a module includes RF-shielding structuresencapsulated within the overmold structure and layered over the overmoldstructure; and in some implementations, the overall dimensions of themodule 75 is not necessarily any larger than a module without theRF-shielding functionality. Accordingly, modules having integratedRF-shielding functionality can advantageously yield a more compactassembled circuit board since external RF-shield structures are notneeded. Further, the packaged modular form allows the modules to behandled easier during manipulation and assembly processes.

The singulated modules can be tested for proper functionality and themodular form allows such testing to be performed easier. Further, themodule's internal EMI/RFI-shielding functionality allows such testing tobe performed without external EMI/RFI-shielding devices.

FIG. 22 shows that in some embodiments, one or more modules included ina circuit board such as a wireless phone board can be configured withone or more packaging features as described herein. Non-limitingexamples of modules that can benefit from such packaging featuresinclude, but are not limited to, a controller module, an applicationprocessor module, an audio module, a display interface module, a memorymodule, a digital baseband processor module, GPS module, anaccelerometer module, a power management module, a transceiver module, aswitching module, and a power amplifier module.

FIG. 23 shows a process 80 that can be implemented to assemble apackaged module having one or more features as described herein on acircuit board. In block 82 a, a packaged module can be provided. In someembodiments, the packaged module can represent a module described inreference to FIG. 22. In block 82 b, the packaged module can be mountedon a circuit board (e.g., a phone board). FIG. 24 schematically depictsa resulting circuit board 90 having module 91 mounted thereon. Thecircuit board can also include other features such as a plurality ofconnections 92 to facilitate operations of various modules mountedthereon.

In block 82 c, a circuit board having modules mounted thereon can beinstalled in a wireless device. FIG. 25 schematically depicts a wirelessdevice 94 (e.g., a cellular phone) having a circuit board 90 (e.g., aphone board). The circuit board 90 is shown to include a module 91having one or more features as described herein. The wireless device isshown to further include other components, such as an antenna 95, a userinterface 96, and a power supply 97.

While embodiments have been described with respect to applyingconductive spray paint to a panel of integrated circuit modules, thedisclosed systems and methods apply to spray painting any surface withedge control to reduce overspray while maintaining paint thicknessuniformity.

The panel 1400 in the illustrated embodiment is a four sided rectangularshape. In other embodiments, the process 12 h of FIG. 15 can be adaptedfor other shapes with more or less than four sides, such as ovals,circles, squares, triangles, trapezoids, and the like.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The words “coupled” or connected”, asgenerally used herein, refer to two or more elements that may be eitherdirectly connected, or connected by way of one or more intermediateelements. Additionally, the words “herein,” “above,” “below,” and wordsof similar import, when used in this application, shall refer to thisapplication as a whole and not to any particular portions of thisapplication. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or” in reference to alist of two or more items, that word covers all of the followinginterpretations of the word: any of the items in the list, all of theitems in the list, and any combination of the items in the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

The above detailed description of certain embodiments is not intended tobe exhaustive or to limit the invention to the precise form disclosedabove. While specific embodiments of, and examples for, the inventionare described above for illustrative purposes, various equivalentmodifications are possible within the scope of the invention, as thoseordinary skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the systems described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

1. (canceled)
 2. A system for spraying a surface of a panel ofintegrated circuit modules with conductive paint, the system comprising:a spray apparatus; computer hardware including at least one computerprocessor; and computer-readable storage having computer-readableinstructions that, when executed by the computer processor, cause thecomputer hardware to control the spray apparatus to perform operationsincluding (i) spraying N axially elongate first bands of conductivepaint including metal particles along a longitudinal axis of a panelincluding integrated circuit modules and advancing along a vertical axisof the panel a first distance after spraying each first band of theconductive paint, and (ii) spraying N+1 axially elongate second bands ofthe conductive paint along the longitudinal axis of the panel andadvancing along the vertical axis of the panel a second distance afterspraying each second band of the conductive paint, the second bands ofthe conductive paint being interspersed between the first bands of theconductive paint to provide an approximately uniform layer of theconductive paint over an upper surface of the panel, the layer ofconductive paint electrically coupling with wirebonds on the panel toform at least part of an electromagnetic interference or radio frequencyinterference shield.
 3. The system of claim 2 wherein a thickness of thelayer of the conductive paint is approximately 25 microns±approximately5 microns.
 4. The system of claim 3 wherein flatness of the layer ofconductive paint is approximately 1% of the thickness of the conductivepaint.
 5. The system of claim 2 wherein the operations further includespraying a layer of conductive paint over the perimeter of the panelprior to spraying the N axially elongate first bands.
 6. The system ofclaim 2 wherein the electromagnetic interference or radio frequencyinterference shield includes the layer of the conductive paint inelectrical contact with a plurality of wirebonds encircling theintegrated circuit module.
 7. The system of claim 2 wherein theoperations further include adjusting at least one parameter of the sprayapparatus chosen from the group consisting of a valve pressure, a needlesize, an air cap, a fluid pressure, an air assist pressure, a fluid ontime, a fluid off time, an air assist on time, an air assist off time, aheight of a nozzle above the upper surface, a travel speed of thenozzle, and an initial position of the nozzle.
 8. The system of claim 7wherein controlling at least one parameter on the spray apparatus isbased on one or both of a metal particle size and a viscosity of theconductive paint.
 9. The system of claim 2 wherein the metal particlesinclude metal flakes having an irregular shape and the approximatelyuniform layer of the conductive paint over the upper surface of thepanel includes approximately covering the upper surface with the metalflakes.
 10. The system of claim 2 wherein N+1 axially elongate secondbands is determined by rounding up a height of the panel minus twice awidth of a perimeter band of the conductive paint divided by a width ofthe second band of the conductive paint to an integer value.
 11. Thesystem of claim 2, wherein the computer-readable instructions areprogrammed by a user.
 12. A system for spraying a surface of a panel ofintegrated circuit modules with conductive paint, the system comprising:a spray apparatus; computer hardware including at least one computerprocessor; and computer-readable storage having computer-readableinstructions that, when executed by the computer processor, cause thecomputer hardware to control the spray apparatus to perform operationsincluding (i) spraying N axially elongate first bands of conductivepaint including metal particles along a longitudinal axis of a panelincluding integrated circuit modules and advancing along a vertical axisof the panel a first distance after spraying each first band of theconductive paint, (ii) spraying a perimeter layer of conductive paintover a perimeter of the panel of integrated circuit modules afterspraying the N axially elongate first bands, the N axially elongatefirst bands being in electrical contact with the perimeter layer ofconductive paint over the perimeter of the panel, and (iii) spraying N+1axially elongate second bands of the conductive paint along thelongitudinal axis of the panel and advancing along the vertical axis ofthe panel a second distance after each second band of the conductivepaint, the second bands of the conductive paint being interspersedbetween the first bands of the conductive paint to provide anapproximately uniform first layer of the conductive paint over an uppersurface of the panel, the layer of conductive paint electricallycoupling with wirebonds on the panel to form at least part of anelectromagnetic interference or radio frequency interference shield. 13.The system of claim 12 wherein a thickness of the layer of theconductive paint is approximately 25 microns±approximately 5 microns.14. The system of claim 13 wherein flatness of the layer of conductivepaint is approximately 1% of the thickness of the conductive paint. 15.The system of claim 14 wherein the computer readable instructionsinclude spraying a first perimeter layer of conductive paint over theperimeter of the panel prior to spraying the N axially elongate firstbands.
 16. The system of claim 15 wherein the computer readableinstructions include determining whether a desired paint thickness hasbeen obtained, and if the desired thickness has not been reached thenrepeating the spraying of the first perimeter layer, the N axiallyelongate first bands, the perimeter layer, and the N+1 axially elongatesecond bands to provide an approximately uniform second layer ofconductive paint over the approximately uniform first layer ofconductive paint.
 17. The system of claim 12 wherein the electromagneticinterference or radio frequency interference shield includes the layerof the conductive paint in electrical contact with a plurality ofwirebonds encircling the integrated circuit module.
 18. The system ofclaim 12 wherein the computer-readable instructions further includecontrolling on the spray apparatus at least one parameter chosen from agroup consisting of a valve pressure, a needle size, an air cap, a fluidpressure, an air assist pressure, a fluid on time, a fluid off time, anair assist on time, an air assist off time, a height of a nozzle abovethe upper surface, a travel speed of the nozzle, and an initial positionof the nozzle.
 19. The system of claim 18 wherein the controlling of theat least one parameter is based on one or both of a metal particle sizeand a viscosity of the conductive paint
 20. The system of claim 12,wherein the computer-readable instructions are programmed by a user.